Metallic glasses with excellent physical and chemical properties are hindered by their size constraints, limiting their practical applications. However, welding technique holds the potential to overcome these limitations. Welding methods of metallic glasses can be classified into liquid phase welding and solid phase welding, each involving distinct mechanisms to form amorphous joints. Effective preventing crystallization is crucial for obtaining high quality joints. This paper provides a systematic and comprehensive review of the research in the field of metallic glass welding, and summarizes the research status of metallic glass and metallic glass welding as well as metallic glass and crystalline metal welding. It focuses on the characteristics and limitations of different welding techniques to achieve fully amorphous welded parts. Additionally, it reviews the research status of metallic glasses as solder materials in brazing process and analyzes the potential applications of metallic glass-based brazing materials, and summarizes approaches for enhancing the mechanical properties of brazed joints. Finally, this paper outlines prospects for the future research and development of metallic glass welding.